lsquic_hcsi_reader.c revision fbc6cc04 
1/* Copyright (c) 2017 - 2020 LiteSpeed Technologies Inc.  See LICENSE. */
2#include <assert.h>
3#include <inttypes.h>
4#include <stddef.h>
5#include <stdint.h>
6#include <string.h>
7#include <sys/queue.h>
8
9#include "lsquic.h"
10#include "lsquic_int_types.h"
11#include "lsquic_varint.h"
12#include "lsquic_hq.h"
13#include "lsquic_hash.h"
14#include "lsquic_conn.h"
15#include "lsquic_hcsi_reader.h"
16
17#define LSQUIC_LOGGER_MODULE LSQLM_HCSI_READER
18#define LSQUIC_LOG_CONN_ID lsquic_conn_log_cid(reader->hr_conn)
19#include "lsquic_logger.h"
20
21#define MIN(a, b) ((a) < (b) ? (a) : (b))
22
23
24void
25lsquic_hcsi_reader_init (struct hcsi_reader *reader,
26        struct lsquic_conn *conn, const struct hcsi_callbacks *callbacks,
27        void *ctx)
28{
29    memset(reader, 0, sizeof(*reader));
30    reader->hr_state = HR_READ_FRAME_BEGIN;
31    reader->hr_conn = conn;
32    reader->hr_cb = callbacks;
33    reader->hr_ctx = ctx;
34    LSQ_DEBUG("initialized");
35}
36
37
38int
39lsquic_hcsi_reader_feed (struct hcsi_reader *reader, const void *buf,
40                                                                size_t bufsz)
41{
42    const unsigned char *p = buf;
43    const unsigned char *const end = p + bufsz;
44
45    const unsigned char *orig_p;
46    uint64_t len;
47    int s;
48
49  continue_reading:
50    while (p < end)
51    {
52        switch (reader->hr_state)
53        {
54        case HR_READ_FRAME_BEGIN:
55            reader->hr_u.vint2_state.vr2s_state = 0;
56            reader->hr_state = HR_READ_FRAME_CONTINUE;
57            /* fall-through */
58        case HR_READ_FRAME_CONTINUE:
59            s = lsquic_varint_read_two(&p, end, &reader->hr_u.vint2_state);
60            if (s < 0)
61                break;
62            reader->hr_frame_type = reader->hr_u.vint2_state.vr2s_one;
63            reader->hr_frame_length = reader->hr_u.vint2_state.vr2s_two;
64            switch (reader->hr_frame_type)
65            {
66            case HQFT_SETTINGS:
67                if (reader->hr_frame_length)
68                {
69                    reader->hr_state = HR_READ_SETTING_BEGIN;
70                    reader->hr_nread = 0;
71                }
72                else
73                {
74                    reader->hr_cb->on_settings_frame(reader->hr_ctx);
75                    reader->hr_state = HR_READ_FRAME_BEGIN;
76                }
77                break;
78            case HQFT_GOAWAY:
79                reader->hr_state = HR_READ_VARINT;
80                break;
81            case HQFT_CANCEL_PUSH:
82                reader->hr_state = HR_READ_VARINT;
83                break;
84            case HQFT_MAX_PUSH_ID:
85                reader->hr_state = HR_READ_VARINT;
86                break;
87            case HQFT_PRIORITY_UPDATE_PUSH:
88            case HQFT_PRIORITY_UPDATE_STREAM:
89                reader->hr_state = HR_READ_VARINT;
90                break;
91            case HQFT_DATA:
92            case HQFT_HEADERS:
93            case HQFT_PUSH_PROMISE:
94                reader->hr_cb->on_unexpected_frame(reader->hr_ctx,
95                                                        reader->hr_frame_type);
96                return -1;
97            default:
98                if (!(reader->hr_frame_type >= 0xB &&
99                        (reader->hr_frame_type - 0xB) % 0x1F == 0))
100                    LSQ_INFO("unknown frame type 0x%"PRIX64" -- skipping",
101                                                        reader->hr_frame_type);
102                reader->hr_state = HR_SKIPPING;
103                LSQ_DEBUG("unknown frame 0x%"PRIX64": will skip %"PRIu64" bytes",
104                            reader->hr_frame_type, reader->hr_frame_length);
105                break;
106            }
107            break;
108        case HR_READ_VARINT:
109            reader->hr_u.vint_state.pos = 0;
110            reader->hr_state = HR_READ_VARINT_CONTINUE;
111            reader->hr_nread = 0;
112            /* fall-through */
113        case HR_READ_VARINT_CONTINUE:
114            orig_p = p;
115            s = lsquic_varint_read_nb(&p, end, &reader->hr_u.vint_state);
116            reader->hr_nread += p - orig_p;
117            if (0 == s)
118            {
119                switch (reader->hr_frame_type)
120                {
121                case HQFT_GOAWAY:
122                case HQFT_CANCEL_PUSH:
123                case HQFT_MAX_PUSH_ID:
124                    if (reader->hr_nread != reader->hr_frame_length)
125                    {
126                        reader->hr_conn->cn_if->ci_abort_error(reader->hr_conn, 1,
127                            HEC_FRAME_ERROR,
128                            "Frame length does not match actual payload length");
129                        reader->hr_state = HR_ERROR;
130                        return -1;
131                    }
132                    break;
133                }
134                switch (reader->hr_frame_type)
135                {
136                case HQFT_GOAWAY:
137                    reader->hr_cb->on_goaway(reader->hr_ctx,
138                                                reader->hr_u.vint_state.val);
139                    break;
140                case HQFT_CANCEL_PUSH:
141                    reader->hr_cb->on_cancel_push(reader->hr_ctx,
142                                                reader->hr_u.vint_state.val);
143                    break;
144                case HQFT_MAX_PUSH_ID:
145                    reader->hr_cb->on_max_push_id(reader->hr_ctx,
146                                                reader->hr_u.vint_state.val);
147                    break;
148                case HQFT_PRIORITY_UPDATE_PUSH:
149                case HQFT_PRIORITY_UPDATE_STREAM:
150                    len = reader->hr_frame_length - reader->hr_nread;
151                    if (len <= (uintptr_t) (end - p))
152                    {
153                        reader->hr_cb->on_priority_update(reader->hr_ctx,
154                            reader->hr_frame_type, reader->hr_u.vint_state.val,
155                            (char *) p, len);
156                        p += len;
157                    }
158                    else if (len <= sizeof(reader->hr_u.prio_state.buf))
159                    {
160                        reader->hr_frame_length = len;
161                        reader->hr_nread = 0;
162                        reader->hr_state = HR_READ_PRIORITY_UPDATE;
163                        goto continue_reading;
164                    }
165                    else
166                    {
167                        p += len;
168                        /* 16 bytes is more than enough for a PRIORITY_UPDATE
169                         * frame, anything larger than that is unreasonable.
170                         */
171                        if (reader->hr_frame_length
172                                        > sizeof(reader->hr_u.prio_state.buf))
173                            LSQ_INFO("skip PRIORITY_UPDATE frame that's too "
174                                    "long (%"PRIu64" bytes)", len);
175                    }
176                    break;
177                default:
178                    assert(0);
179                }
180                reader->hr_state = HR_READ_FRAME_BEGIN;
181                break;
182            }
183            else
184            {
185                assert(p == end);
186                return 0;
187            }
188        case HR_SKIPPING:
189            len = MIN((uintptr_t) (end - p), reader->hr_frame_length);
190            p += len;
191            reader->hr_frame_length -= len;
192            if (0 == reader->hr_frame_length)
193                reader->hr_state = HR_READ_FRAME_BEGIN;
194            break;
195        case HR_READ_SETTING_BEGIN:
196            reader->hr_u.vint2_state.vr2s_state = 0;
197            reader->hr_state = HR_READ_SETTING_CONTINUE;
198            /* fall-through */
199        case HR_READ_SETTING_CONTINUE:
200            orig_p = p;
201            s = lsquic_varint_read_two(&p, end, &reader->hr_u.vint2_state);
202            reader->hr_nread += p - orig_p;
203            if (reader->hr_nread > reader->hr_frame_length)
204            {
205                reader->hr_conn->cn_if->ci_abort_error(reader->hr_conn, 1,
206                    HEC_FRAME_ERROR, "SETTING frame contents too long");
207                reader->hr_state = HR_ERROR;
208                return -1;
209            }
210            if (s < 0)
211                break;
212            reader->hr_cb->on_setting(reader->hr_ctx,
213                    reader->hr_u.vint2_state.vr2s_one,
214                    reader->hr_u.vint2_state.vr2s_two);
215            if (reader->hr_nread >= reader->hr_frame_length)
216            {
217                reader->hr_state = HR_READ_FRAME_BEGIN;
218                reader->hr_cb->on_settings_frame(reader->hr_ctx);
219            }
220            else
221                reader->hr_state = HR_READ_SETTING_BEGIN;
222            break;
223        case HR_READ_PRIORITY_UPDATE:
224            len = MIN((uintptr_t) (end - p),
225                            reader->hr_frame_length - reader->hr_nread);
226            memcpy(reader->hr_u.prio_state.buf + reader->hr_nread, p, len);
227            reader->hr_nread += len;
228            p += len;
229            if (reader->hr_frame_length == reader->hr_nread)
230            {
231                reader->hr_cb->on_priority_update(reader->hr_ctx,
232                        reader->hr_frame_type, reader->hr_u.vint_state.val,
233                        reader->hr_u.prio_state.buf, reader->hr_frame_length);
234                reader->hr_state = HR_READ_FRAME_BEGIN;
235            }
236            break;
237        default:
238            assert(0);
239            /* fall-through */
240        case HR_ERROR:
241            return -1;
242        }
243    }
244
245    return 0;
246}
247